Question: Solve for $x$ and $y$ using substitution. ${2x-2y = 10}$ ${y = 6x-10}$
Since $y$ has already been solved for, substitute $6x-10$ for $y$ in the first equation. ${2x - 2}{(6x-10)}{= 10}$ Simplify and solve for $x$ $2x-12x + 20 = 10$ $-10x+20 = 10$ $-10x+20{-20} = 10{-20}$ $-10x = -10$ $\dfrac{-10x}{{-10}} = \dfrac{-10}{{-10}}$ ${x = 1}$ Now that you know ${x = 1}$ , plug it back into $\thinspace {y = 6x-10}\thinspace$ to find $y$ ${y = 6}{(1)}{ - 10}$ $y = 6 - 10$ $y = -4$ You can also plug ${x = 1}$ into $\thinspace {2x-2y = 10}\thinspace$ and get the same answer for $y$ : ${2}{(1)}{ - 2y = 10}$ ${y = -4}$